For communication with a mobile communication terminal or UE (user equipment), usually the so-called “paging” is performed, e.g. between UE and eNodeB (i.e. the base station) to ensure that the UE can receive data.
In order to be able to react to paging, a UE listens to the so-called paging channels. In order to save energy, the paging channels are not continuously monitored, but only at certain times, the so-called Paging Occasions (PO). For example, if a device listens to the paging channel five times for one second every 10 seconds, the power consumption for the receiving part drops by about 5/10=½ by day, i.e. about 50%.
For the communication between machines or so-called “connected things” on the Internet of Things (IoT), there may be the need for some applications to further reduce the energy consumption of battery-operated transceivers.
A main application case, often referred to in the context of IoT, is the case of massive IoT. In this case, the 5G (fifth generation) communication network should be able to operate and manage the use case of a large number of these components or IoTs. In this context, there is a need to reduce the energy consumption of IoT devices and to keep the impact on the 5G network as low as possible.
A method used to reduce the energy consumption of these devices is the expansion of the so-called DRX (Discontinuous Reception) cycles. In that method, the time interval between two times during which the UE listens to the paging channels is increased. I.e., if the paging channel is listened for example once per day for only one second, then the power consumption is decreased by (86400−1)/86400=0.9999, i.e. by about 99%.
This saving in energy is, however, due to the fact that the terminal can only be reached again once per day for about one second to inform it of upcoming data for the device.
Data traffic to the UE is therefore temporarily stored and transferred to the UE only when the UE is reachable and reacts to a paging. This means, however, that the data must be stored temporarily, which can be very resource-intensive.